1
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Gul G, Faller R, Ileri-Ercan N. Coarse-grained modeling of polystyrene-modified CNTs and their interactions with lipid bilayers. Biophys J 2023; 122:1748-1761. [PMID: 37056052 PMCID: PMC10209035 DOI: 10.1016/j.bpj.2023.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 03/31/2023] [Accepted: 04/05/2023] [Indexed: 04/15/2023] Open
Abstract
In the present work, we describe Martini3 coarse-grained models of polystyrene and carboxyl-terminated polystyrene functionalized carbon nanotubes (CNTs) and investigate their interactions with lipid bilayers with and without cholesterol (CHOL) using molecular dynamics simulations. By changing the polystyrene chain length and grafting density at the end ring of the CNTs at two different nanotube concentrations, we observe the translocation of nanoparticles as well as changes in the lipid bilayer properties. Our results show that all developed models passively diffuse into the membranes without causing any damage to the membrane integrity, although high concentrations of CNTs induce structural and elastic changes in lipid bilayers. In the presence of CHOL, increasing CNT concentration results in decreased rates of CHOL transmembrane motions. On the other hand, CNTs are prone to lipid and polystyrene blockage, which affects their equilibrated configurations, and tilting behavior within the membranes. Hence, we demonstrate that polystyrene-functionalized CNTs are promising drug-carrier agents. However, polystyrene chain length and grafting density are important factors to consider to enhance the efficiency of drug delivery.
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Affiliation(s)
- Gulsah Gul
- Department of Chemical Engineering, Bogazici University, Istanbul, Turkey; Department of Chemical Engineering, University of California, Davis, Davis, California
| | - Roland Faller
- Department of Chemical Engineering, University of California, Davis, Davis, California
| | - Nazar Ileri-Ercan
- Department of Chemical Engineering, Bogazici University, Istanbul, Turkey.
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2
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Gul G, Faller R, Ileri-Ercan N. Polystyrene-modified carbon nanotubes: Promising carriers in targeted drug delivery. Biophys J 2022; 121:4271-4279. [PMID: 36230001 PMCID: PMC9703093 DOI: 10.1016/j.bpj.2022.10.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 08/28/2022] [Accepted: 10/11/2022] [Indexed: 12/14/2022] Open
Abstract
To design drug-delivery agents for therapeutic and diagnostic applications, understanding the mechanisms by which covalently functionalized carbon nanotubes penetrate and interact with cell membranes is of great importance. Here, we report all-atom molecular dynamics results from polystyrene and carboxyl-terminated polystyrene-modified carbon nanotubes and show their translocation behavior across a model lipid bilayer together with their potential to deliver a molecule of the drug ibuprofen into the cell. Our results indicate that functionalized carbon nanotubes are internalized by the membrane in hundreds of nanoseconds and that drug loading increases the internalization speed further. Both loaded and unloaded tubes cross the closest leaflet of the bilayer by nonendocytic pathways, and for the times studied, the drug molecule remains trapped inside the pristine tube while remaining attached at the end of polystyrene-modified tube. On the other hand, carboxyl-terminated polystyrene functionalization allows the drug to be completely released into the lower leaflet of the bilayer without imposing damage to the membrane. This study shows that polystyrene functionalization is a promising alternative and facilitates drug delivery as a benchmark case.
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Affiliation(s)
- Gulsah Gul
- Department of Chemical Engineering, Bogazici University, Bebek, Istanbul, Turkey; Department of Chemical Engineering, University of California, Davis, Davis, California
| | - Roland Faller
- Department of Chemical Engineering, University of California, Davis, Davis, California
| | - Nazar Ileri-Ercan
- Department of Chemical Engineering, Bogazici University, Bebek, Istanbul, Turkey.
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3
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Derry PJ, Nilewski LG, Sikkema WKA, Mendoza K, Jalilov A, Berka V, McHugh EA, Tsai AL, Tour JM, Kent TA. Catalytic oxidation and reduction reactions of hydrophilic carbon clusters with NADH and cytochrome C: features of an electron transport nanozyme. NANOSCALE 2019; 11:10791-10807. [PMID: 31134256 PMCID: PMC10863654 DOI: 10.1039/c9nr00807a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Previously, our group reported on the promising efficacy of poly(ethylene glycol)-hydrophilic carbon clusters (PEG-HCCs) to work as broadly active and high capacity antioxidants in brain ischemia and injury models including stroke and traumatic brain injury coupled with hemorrhagic shock. PEG-HCCs are a carbon nanomaterial derived from harsh oxidation of single wall carbon nanotubes and covalently modified with poly(ethylene glycol). They retain no tubular remnants and are composed of a highly oxidized carbon core functionalized with epoxy, peroxyl, quinone, ketone, carboxylate, and hydroxyl groups. HCCs are the redox active carbon core of PEG-HCCs, which have a broad reduction potential range starting at +200 mV and extending to -2 V. Here we describe a new property of these materials: the ability to catalytically transfer electrons between key surrogates and proteins of the mitochondrial electron transport complex in a catalytic fashion consistent with the concept of a nanozyme. The estimated reduction potential of PEG-HCCs is similar to that of ubiquinone and they enabled the catalytic transfer of electrons from low reduction potential species to higher reduction electron transport complex constituents. PEG-HCCs accelerated the reduction of resazurin (a test indicator of mitochondrial viability) and cytochrome c by NADH and ascorbic acid in solution. Kinetic experiments suggested a transient tertiary complex. Electron paramagnetic resonance demonstrated NADH increased the magnitude of PEG-HCCs' intrinsic radical, which then reduced upon subsequent addition of cytochrome c or resazurin. Deconvolution microscopy identified PEG-HCCs in close proximity to mitochondria after brief incubation with cultured SHSY-5Y human neuroblastoma cells. Compared to methylene blue (MB), considered a prototypical small molecule electron transport shuttle, PEG-HCCs were more protective against toxic effects of hydrogen peroxide in vitro and did not demonstrate impaired cell viability as did MB. PEG-HCCs were protective in vitro when cells were exposed to sodium cyanide, a mitochondrial complex IV poison. Because mitochondria are a major source of free radicals in pathology, we suggest that this newly described nanozyme action helps explain their in vivo efficacy in a range of injury models. These findings may also extend their use to mitochondrial disorders.
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Affiliation(s)
- Paul J. Derry
- Texas A&M Health Science Center Institute of
Biosciences and Technology, Houston, Texas 77030, United States
- Neurology and Center for Translational Research in
Inflammatory Diseases, Michel E. DeBakey VA Medical Center, Houston, Texas 77030,
United States
| | - Lizanne G. Nilewski
- Department of Chemistry, Rice University, 6100
Main Street, Houston, Texas 77005, United States
| | - William K. A. Sikkema
- Department of Chemistry, Rice University, 6100
Main Street, Houston, Texas 77005, United States
| | - Kimberly Mendoza
- Department of Chemistry, Rice University, 6100
Main Street, Houston, Texas 77005, United States
| | - Almaz Jalilov
- Department of Chemistry and Center for Integrative
Petroleum Research, King Fahd University of Petroleum and Minerals, Dhahran, Saudi
Arabia, 31261
| | - Vladimir Berka
- Hematology, Internal Medicine, University of Texas
Houston Medical School, Houston, Texas 77030, United States
| | - Emily A. McHugh
- Department of Chemistry, Rice University, 6100
Main Street, Houston, Texas 77005, United States
| | - Ah-Lim Tsai
- Hematology, Internal Medicine, University of Texas
Houston Medical School, Houston, Texas 77030, United States
| | - James M. Tour
- Department of Chemistry, Rice University, 6100
Main Street, Houston, Texas 77005, United States
- The NanoCarbon Center, Rice University, 6100 Main
Street, Houston, Texas 77005, United States
- Department of Materials Science and
NanoEngineering, Rice University, 6100 Main Street, Houston, Texas 77005, United
States
| | - Thomas A. Kent
- Department of Chemistry, Rice University, 6100
Main Street, Houston, Texas 77005, United States
- Stanley H. Appel Department of Neurology, Houston
Methodist Hospital and Institute of Academic Medicine, Houston, Texas 77030, United
States
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4
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Nilewski L, Mendoza K, Jalilov AS, Berka V, Wu G, Sikkema WKA, Metzger A, Ye R, Zhang R, Luong DX, Wang T, McHugh E, Derry PJ, Samuel EL, Kent TA, Tsai AL, Tour JM. Highly Oxidized Graphene Quantum Dots from Coal as Efficient Antioxidants. ACS APPLIED MATERIALS & INTERFACES 2019; 11:16815-16821. [PMID: 30995006 DOI: 10.1021/acsami.9b01082] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Graphene quantum dots (GQDs) have recently been employed in various fields including medicine as antioxidants, primarily because of favorable biocompatibility in comparison to common inorganic quantum dots, although the structural features that lead to the biological activities of GQDs are poorly understood. Here, we report that coal-derived GQDs and their poly(ethylene glycol)-functionalized derivatives serve as efficient antioxidants, and we evaluate their electrochemical, chemical, and in vitro biological activities.
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Affiliation(s)
| | - Kimberly Mendoza
- Department of Neurology , Baylor College of Medicine , Houston , Texas 77030 , United States
| | | | - Vladimir Berka
- Hematology, Internal Medicine . University of Texas McGovern Medical School-Houston , Houston , Texas 77030 , United States
| | - Gang Wu
- Hematology, Internal Medicine . University of Texas McGovern Medical School-Houston , Houston , Texas 77030 , United States
| | | | | | | | | | | | | | | | - Paul J Derry
- Institute of Biosciences and Technology , Texas A&M Health Science Center , Houston , Texas 77030 , United States
| | - Errol Loïc Samuel
- Department of Neurology , Baylor College of Medicine , Houston , Texas 77030 , United States
| | - Thomas A Kent
- Institute of Biosciences and Technology , Texas A&M Health Science Center , Houston , Texas 77030 , United States
- Stanley H. Appel Department of Neurology and Research Institute , Houston Methodist Hospital , Houston , Texas 77030 , United States
| | - Ah-Lim Tsai
- Hematology, Internal Medicine . University of Texas McGovern Medical School-Houston , Houston , Texas 77030 , United States
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5
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Meran M, Akkus PD, Kurkcuoglu O, Baysak E, Hizal G, Haciosmanoglu E, Unlu A, Karatepe N, Güner FS. Noncovalent Pyrene-Polyethylene Glycol Coatings of Carbon Nanotubes Achieve in Vitro Biocompatibility. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:12071-12082. [PMID: 30231197 DOI: 10.1021/acs.langmuir.8b00971] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Single-walled carbon nanotubes (SWNTs) have become increasingly exploited in biological applications, such as imaging and drug delivery. The application of SWNTs in biological settings requires the surface chemistry to remain through the low solubility in aqueous media. In this research, a facile approach for the preparation of a polyethylene glycol (PEG)-coated SWNT-based nanocarrier was reported. We focused on the effect of PEG chain length and SWNT size on the cytotoxicity of PEG-coated SWNTs as a superior drug delivery nanovector. First, all-atom molecular dynamics (MD) simulations were employed to explore the stability and behavior of SWNT/pyrene-PEG (SWNT/Pyr-PEG) structures at a molecular level that is not attainable with experiments. The MD studies revealed that (i) π-π stacking interactions between the pyrene bearing PEG molecules and SWNTs are maintained in bulky situations, regardless of PEG molecular weight or SWNT size; (ii) pyrene molecules diffuse over the SWNT surface without detaching; and (iii) both short and long dynamic Pyr-PEG chains have the capability of effectively coating the SWNT surface. In light of the simulations, noncovalent (π-π stacking) assemblies of SWNT/Pyr-PEG with different molecular weights of PEG ( Mw = 2000, 5000, and 12000) were successfully fabricated and characterized. For longer PEG chains, more effective coating of SWNTs was obtained, resulting in more biocompatible SWNT/Pyr-PEG nanomaterials. The number of SWNTs coated by Pyr-PEG was highly dependent on the length of pyrene bearing PEG polymers. Moreover, the short SWNTs showed a higher amount of PEG coating with respect to the long SWNTs. Cell viability results demonstrated a dose-dependent cytotoxicity of coated SWNTs. Short SWNTs coated with longer PEG chains have low cytotoxicity to be used in in vivo studies.
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Affiliation(s)
- Mehdi Meran
- Department of Chemical Engineering , Istanbul Technical University , 34469 Istanbul , Turkey
| | - Pelin Deniz Akkus
- Department of Chemical Engineering , Istanbul Technical University , 34469 Istanbul , Turkey
| | - Ozge Kurkcuoglu
- Department of Chemical Engineering , Istanbul Technical University , 34469 Istanbul , Turkey
| | - Elif Baysak
- Department of Chemistry , Istanbul Technical University , 34469 Istanbul , Turkey
| | - Gurkan Hizal
- Department of Chemistry , Istanbul Technical University , 34469 Istanbul , Turkey
| | - Ebru Haciosmanoglu
- Department of Physiology, Faculty of Medicine , Istanbul Bilim University , 34394 Istanbul , Turkey
| | - Ayhan Unlu
- Department of Biophysics, Faculty of Medicine , Trakya University , 22030 Edirne , Turkey
| | - Nilgun Karatepe
- Energy Institute, Renewable Energy Division , Istanbul Technical University , 34469 Istanbul , Turkey
| | - F Seniha Güner
- Department of Chemical Engineering , Istanbul Technical University , 34469 Istanbul , Turkey
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6
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Nilewski LG, Singh M, Baskin DS, Tour JM, Sharpe MA. Transfer of Dyes and Drugs into Cells Using EGFR-Targeted Nanosyringes. ACS Chem Neurosci 2018; 9:107-117. [PMID: 28753296 DOI: 10.1021/acschemneuro.7b00138] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Selective targeting of drug loaded nanovectors to specific epitopes highly expressed on the surface of cancer cells is a goal for nanotechnologists. We have modified our previously described PEGylated-hydrophilic carbon clusters (PEG-HCCs) so that the epidermal growth factor receptor (EGFR) binding peptide, GE11, is attached using click chemistry at the end of each PEG. The resulting nanosyringe, PepEGFR-PEG-HCC, can be loaded with a wide range of hydrophobic drugs and dyes. We show that, both in vitro and in vivo, this payload can be delivered to cancer cells expressing EGFR. We can observe the activation of EGFR and track the normal physiological internalization and recycling/signaling pathways of this tyrosine kinase following binding of PepEGFR-PEG-HCC. We also demonstrate the competitive binding of the nanosyringe to EGFR with its normal activator, EGF, as well as observing the colocalization of the nanosyringe with clathrin, the coated pit integral protein. The internalization of the drug/dye loaded nanosyringe can be inhibited by using anti-EGFR antibodies, the drug erlotinib, or Pitstop-1, the clathrin coated pit formation specific inhibitor. To further demonstrate the specificity of the drug loaded nanovectors, we demonstrated that, in both flank and intracranial xenograft mouse models, dye delivery is highly specific to tumors and no other tissues. Finally, using nanosyringes loaded with esterase sensitive fluorescein diacetate, we demonstrated that the drug payloads can be in vivo delivered to the cytosol of cancer cells within the mouse brain.
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Affiliation(s)
| | - Melissa Singh
- Fannin Innovation Studio, 3900
Essex Lane, Suite 575, Houston, Texas 77027, United States
| | - David S. Baskin
- Kenneth
R. Peak Brain and Pituitary Tumor Center, Department of Neurosurgery, Houston Methodist Hospital, Houston, Texas 77030, United States
| | | | - Martyn A. Sharpe
- Kenneth
R. Peak Brain and Pituitary Tumor Center, Department of Neurosurgery, Houston Methodist Hospital, Houston, Texas 77030, United States
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7
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Gao Z, Varela JA, Groc L, Lounis B, Cognet L. Toward the suppression of cellular toxicity from single-walled carbon nanotubes. Biomater Sci 2017; 4:230-44. [PMID: 26678092 DOI: 10.1039/c5bm00134j] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In the multidisciplinary fields of nanobiology and nanomedicine, single-walled carbon nanotubes (SWCNTs) have shown great promise due to their unique morphological, physical and chemical properties. However, understanding and suppressing their cellular toxicity is a mandatory step before promoting their biomedical applications. In light of the flourishing recent literature, we provide here an extensive review on SWCNT cellular toxicity and an attempt to identify the key parameters to be considered in order to obtain SWCNT samples with minimal or no cellular toxicity.
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Affiliation(s)
- Zhenghong Gao
- Univ. Bordeaux, Laboratoire Photonique Numerique et Nanosciences, UMR 5298, F-33400 Talence, France and Institut d'Optique & CNRS, LP2N UMR 5298, F-33400 Talence, France.
| | - Juan A Varela
- Univ. Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, F-33000 Bordeaux, France and CNRS, IINS UMR 5297, F-33000 Bordeaux, France
| | - Laurent Groc
- Univ. Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, F-33000 Bordeaux, France and CNRS, IINS UMR 5297, F-33000 Bordeaux, France
| | - Brahim Lounis
- Univ. Bordeaux, Laboratoire Photonique Numerique et Nanosciences, UMR 5298, F-33400 Talence, France and Institut d'Optique & CNRS, LP2N UMR 5298, F-33400 Talence, France.
| | - Laurent Cognet
- Univ. Bordeaux, Laboratoire Photonique Numerique et Nanosciences, UMR 5298, F-33400 Talence, France and Institut d'Optique & CNRS, LP2N UMR 5298, F-33400 Talence, France.
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8
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Silva E, Vasconcellos LMRD, Rodrigues BVM, Dos Santos DM, Campana-Filho SP, Marciano FR, Webster TJ, Lobo AO. PDLLA honeycomb-like scaffolds with a high loading of superhydrophilic graphene/multi-walled carbon nanotubes promote osteoblast in vitro functions and guided in vivo bone regeneration. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 73:31-39. [PMID: 28183613 DOI: 10.1016/j.msec.2016.11.075] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 10/24/2016] [Accepted: 11/21/2016] [Indexed: 12/25/2022]
Abstract
Herein, we developed honeycomb-like scaffolds by combining poly (d, l-lactic acid) (PDLLA) with a high amount of graphene/multi-walled carbon nanotube oxides (MWCNTO-GO, 50% w/w). From pristine multi-walled carbon nanotubes (MWCNT) powders, we produced MWCNTO-GO via oxygen plasma etching (OPE), which promoted their exfoliation and oxidation. Initially, we evaluated PDLLA and PDLLA/MWCNTO-GO scaffolds for tensile strength tests, cell adhesion and cell viability (with osteoblast-like MG-63 cells), alkaline phosphatase (ALP, a marker of osteoblast differentiation) activity and mineralized nodule formation. In vivo tests were carried out using PDLLA and PDLLA/MWCNTO-GO scaffolds as fillers for critical defects in the tibia of rats. MWCNTO-GO loading was responsible for decreasing the tensile strength and elongation-at-break of PDLLA scaffolds, although the high mechanical performance observed (~600MPa) assures their application in bone tissue regeneration. In vitro results showed that the scaffolds were not cytotoxic and allowed for osteoblast-like cell interactions and the formation of mineralized matrix nodules. Furthermore, MG-63 cells grown on PDLLA/MWCNTO-GO significantly enhanced osteoblast ALP activity compared to controls (cells alone), while the PDLLA group showed similar ALP activity when compared to controls and PDLLA/MWCNTO-GO. Most impressively, in vivo tests suggested that compared to PDLLA scaffolds, PDLLA/MWCNTO-GO had a superior influence on bone cell activity, promoting greater new bone formation. In summary, the results of this study highlighted that this novel scaffold (MWCNTO-GO, 50% w/w) is a promising alternative for bone tissue regeneration and, thus, should be further studied.
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Affiliation(s)
- Edmundo Silva
- Laboratory of Biomedical Nanotechnology, University of Vale do Paraiba, Av. Shishima Hifumi 2911, Sao Jose dos Campos 12224-000, São Paulo, Brazil
| | - Luana Marotta Reis de Vasconcellos
- Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, State University of Sao Paulo (UNESP), Av. Engenheiro Francisco Jose Longo, 777, Sao Jose dos Campos 12245-000, SP, Brazil
| | - Bruno V M Rodrigues
- Laboratory of Biomedical Nanotechnology, University of Vale do Paraiba, Av. Shishima Hifumi 2911, Sao Jose dos Campos 12224-000, São Paulo, Brazil; Laboratory of Biomedical Nanotechnology, Biomedical Engineering Innovation Center, Universidade Brasil, Rua Carolina Fonseca 235, 08230-030, São Paulo, Brazil
| | - Danilo Martins Dos Santos
- Chemistry Institute of Sao Carlos, University of Sao Paulo, Av. Trabalhador Sao-Carlense, 400, 13566-590 Sao Carlos, SP, Brazil
| | - Sergio P Campana-Filho
- Chemistry Institute of Sao Carlos, University of Sao Paulo, Av. Trabalhador Sao-Carlense, 400, 13566-590 Sao Carlos, SP, Brazil
| | - Fernanda Roberta Marciano
- Laboratory of Biomedical Nanotechnology, University of Vale do Paraiba, Av. Shishima Hifumi 2911, Sao Jose dos Campos 12224-000, São Paulo, Brazil; Laboratory of Biomedical Nanotechnology, Biomedical Engineering Innovation Center, Universidade Brasil, Rua Carolina Fonseca 235, 08230-030, São Paulo, Brazil; Department of Medicine, Biomaterials Innovation Research Center, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA; Department of Chemical Engineering, Northeastern University, Boston, MA 02115, USA
| | - Thomas J Webster
- Department of Chemical Engineering, Northeastern University, Boston, MA 02115, USA
| | - Anderson Oliveira Lobo
- Laboratory of Biomedical Nanotechnology, University of Vale do Paraiba, Av. Shishima Hifumi 2911, Sao Jose dos Campos 12224-000, São Paulo, Brazil; Laboratory of Biomedical Nanotechnology, Biomedical Engineering Innovation Center, Universidade Brasil, Rua Carolina Fonseca 235, 08230-030, São Paulo, Brazil; Department of Medicine, Biomaterials Innovation Research Center, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA; Department of Chemical Engineering, Northeastern University, Boston, MA 02115, USA.
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9
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Baranowska-Korczyc A, Jasiurkowska-Delaporte M, Maciejewska BM, Warowicka A, Coy LE, Zalewski T, Kozioł KK, Jurga S. PEG–MWCNT/Fe hybrids as multi-modal contrast agents for MRI and optical imaging. RSC Adv 2016. [DOI: 10.1039/c6ra09191a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This study examines the use of oxidized multi-walled carbon nanotube/iron (O-MWCNT/Fe) nanohybrids modified with polyethylene glycol (PEG) as multifunctional cellular imaging agents for magnetic resonance imaging (MRI) and fluorescence microscopy.
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Affiliation(s)
| | | | - Barbara M. Maciejewska
- NanoBioMedical Centre
- Adam Mickiewicz University
- PL-61614 Poznań
- Poland
- Department of Macromolecular Physics
| | - Alicja Warowicka
- NanoBioMedical Centre
- Adam Mickiewicz University
- PL-61614 Poznań
- Poland
| | - L. Emerson Coy
- NanoBioMedical Centre
- Adam Mickiewicz University
- PL-61614 Poznań
- Poland
| | - Tomasz Zalewski
- NanoBioMedical Centre
- Adam Mickiewicz University
- PL-61614 Poznań
- Poland
| | - Krzysztof K. Kozioł
- University of Cambridge
- Department of Materials Science and Metallurgy
- Cambridge CB3 0FS
- UK
| | - Stefan Jurga
- NanoBioMedical Centre
- Adam Mickiewicz University
- PL-61614 Poznań
- Poland
- Department of Macromolecular Physics
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10
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Highly efficient conversion of superoxide to oxygen using hydrophilic carbon clusters. Proc Natl Acad Sci U S A 2015; 112:2343-8. [PMID: 25675492 DOI: 10.1073/pnas.1417047112] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many diseases are associated with oxidative stress, which occurs when the production of reactive oxygen species (ROS) overwhelms the scavenging ability of an organism. Here, we evaluated the carbon nanoparticle antioxidant properties of poly(ethylene glycolated) hydrophilic carbon clusters (PEG-HCCs) by electron paramagnetic resonance (EPR) spectroscopy, oxygen electrode, and spectrophotometric assays. These carbon nanoparticles have 1 equivalent of stable radical and showed superoxide (O2 (•-)) dismutase-like properties yet were inert to nitric oxide (NO(•)) as well as peroxynitrite (ONOO(-)). Thus, PEG-HCCs can act as selective antioxidants that do not require regeneration by enzymes. Our steady-state kinetic assay using KO2 and direct freeze-trap EPR to follow its decay removed the rate-limiting substrate provision, thus enabling determination of the remarkable intrinsic turnover numbers of O2 (•-) to O2 by PEG-HCCs at >20,000 s(-1). The major products of this catalytic turnover are O2 and H2O2, making the PEG-HCCs a biomimetic superoxide dismutase.
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11
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Lee H. Dispersion and bilayer interaction of single-walled carbon nanotubes modulated by covalent and noncovalent PEGylation. MOLECULAR SIMULATION 2014. [DOI: 10.1080/08927022.2014.976638] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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12
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Cristancho D, Benitez L, Seminario JM. Coupling of mechanical and electronic properties of carbon nanotubes. J Mol Model 2013; 19:5237-44. [PMID: 24126827 DOI: 10.1007/s00894-013-2019-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 09/22/2013] [Indexed: 11/26/2022]
Abstract
Because of the potential importance of carbon nanotubes (CNT) in renewable energy and other fields, molecular orbital ab initio calculations are used to study the relation between mechanical and electronic properties of such structures. We estimate a modulus of elasticity of 1.3 TPa and find out that the mechanism of CNT structure deformation is dependent on their chirality. Armchair and chiral nanotubes have ductile deformation fracture while zigzag have both ductile and brittle; on the other hand armchair nanotubes fracture and form two caps while chiral nanotubes adopt a helical-structure conformation. In addition, the energy gap between occupied and unoccupied molecular orbitals increases when nanotubes are under plastic deformation. This strong coupling between mechanical and electrical properties can be used to tune CNT mechanically to specific electronic bandgaps, affecting directly their electromagnetic absorption properties.
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Affiliation(s)
- Dahiyana Cristancho
- Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
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